Underbody



Feb. 15, 1938. R. s. BEGG 2,108,191

UNDERBODY Filed July 9, 1936 4 Sheets-Sheet l If ii ii 72 4 -2: 3

.Qzwse/Z @8 7 Feb. 15, 1938. R. s B EGG UNDERBODY Fined July 9, 1936 4 Sheets-Sheet 2 R. S. BEGG Feb. 15, 1938.

UNDERBODY Filed July 9, 1936 4 Sheets-Sheet 3 I gwucxwto'n ZusselL-S 93w FeB. 15, 1938.

R. S. BEGG UNDERBODY Filed July 9, 1956 4 Sheets-Sheet 4 ZJSdti 'PATNT orric UNDERBOD-Y Russell S. Begg, Detroit,

Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Application July 9, 1936, SerialNo. 89,693

14 Claims.

This invention relates to. metal automobile bodies and has particular reference to an im provement in an underbody or under-pan to sup port the superstructure.

The invention relates to a body of the type in .which the usual chassis is eliminated and the underpan made suiiiciently strong to support the superstructure. In the present instance the superstructure is substantially the same as that shownin the copending application of Earle S. MacPherson, Ser. No. 34,781. V

The novelty of the invention relates to specific details in construction of the underpan as will be later described and claimed;

. On the drawings Figure 1 is a side elevational view of a portion ofan automotive vehicle to which the invention is applied.

Figures 2 and 3 are sections on the corresponding lines of Figure 7.

Figure 4 is a section on the line i4 of Figure Figure 5 is a side elevational view of the underpan;

' Figure 6 is a bottom plan View thereof.

Figure '7 is a top plan View thereof.

Figures 8-12 inclusive are sections on the corresponding lines of Figure 7.

Figures 13, 14,- and 15 are views on the corresponding lines of Figure: 6. a

Referring to Figure 1 of the drawings, the numeral 2 indicates an automobile body as a whole. Thebod-y has the rear door lhaving the handle Gland hinged at its bottom as at: 8 (Figure 3). The rear fenders are indicated at if], the rear doors at H, the front doors at l2 and the intermediate post at M. The front fenders are indicated at IS, the cowl at 2%, the hood at 22, radiator grille at 24, headlamps at 26 and the wheels at j 28. The front Wheels are independently sprung byany suitable independent springing means while the rear wheels are mounted on the conventional leaf springs 3d. The vehicle or "body of the. invention has no running board.

Referring to Figure '7 the underpan of the vehicle is indicatedas a whole at 32and comprises the forward wider part M and the rear narrower part 36. The part. 36 is made narrower because it must be receivedgbetween the rear wheels 30 of the vehicle, while the Wider part extends the full width of the vehicle or beyond the usual gage of the wheels. 3

Referring to Figures 2-4 inclusive, the rear of ..the narrower; portion 36 of the underpan has a dflwnturned inclined flange 38 best disclosed in Figure 3. The downturned flange ends in a short downwardly turned flange portion 49 which mates with a flange 42 on a transverse plate M the ends of which are downturned in the form of flanges it. The main portion of the plate d4 extends upwardly and forwardly and ends in the downturned flange it}. A second transverse plate 58 is welded at its lower end as at 52 to the flange 48 of the plate 44 and at its upper end it is rearwardly flanged as at M and is welded to the bottom of the rear porno-n36. The. plates 44, 5t, and the flange 33 form a box-sectioned construction at the rear of the vehicle.

The transverse plate 4Q intermediate its ends has two inwardly pressed portions or bulges 56 formed therein. The bulge is upwardly pressed until the rear side 58 thereof abuts against the rear flange 38 where the two mating faces are welded together. This structure forms recesses for the reception of the wing fit of the hinge 8 on which the rear door 1 is swung.

Likewise welded to the mating faces 53 of the: bulge 56 and the rear flange 3% is the right -angular member 62 extending the width of the door and with one wing secured to the flange 3t and the other projecting rearwardly. The door t has a channel 64 formed therein in which there. is received a strip of soft rubber 66 which is adapted to strike against and be compressed by the member 62 when the door is in closed position.

This forms a weather tight construction and prevents the entrance of foreign matter into the rear compartment of the vehicle. A similar construction may be placed at the sides and top of the door.

The side edges of the rear narrow portion 36 have the downturned flanges 68 (Figure 4) which in turn vhave a short outwardly turned flange it which mates With the corresponding flange l2 on a channel member "M. The inner sidelt of the channel member has a short flange '28 which abuts against the underside of the underpan 36 and. is welded thereto. The flanges 73 and T2 are likewise welded together and form a box section which extends from the rear extremity of the vehicle forwardly for the entire extent of the narrow portion 36 (as is best shown in Figure 6) and also extends for a portion of the way along the underside of the forward wider portion it as is shown at 8t. The channel member M then is turned outwardly as shown at 82 and meets the side edge of the wider portion 3d at M, which is also the place at which the door post it meets the side of the underpan.

The transverse plate 50 of Figure 3 has the rearwardly turned flange 86 indicated in dotted line in Figure 2 and in full line in Figure 4. This flange is spot-welded to the side 16 of the channel member 14. The plate 44 extends the full width of the rear of the vehicle and at the edge of the underpan is welded to the underside of thechannel 14 at 88. The downwardly turned flange 46 at the ends of the plate 44 are curved or arched as shown in Figures 4 and 7, the curved or arched portion conforming to the curve or arch of the rear wheel housing I0.

As will be apparent from an examination of Figures 3 and '7 the flange 38 at the rear of the underpan is given a different formation at the extreme side portions of the underpan. This is indicated by the numeral in Figures 2, 3, and 7. The reason for this construction is to cause a continuation of the side box-sectioned construction to the extreme tip of the vehicle and also to form a flat surface as shown in Figure 2 to which the rear bumper may be applied. In order to strengthen the rear construction for the rear bumper, a U-shaped reinforcing element 92 is secured inside the box-sectioned construction formed by the lateral flange 68 and the channel member 74. This U-shaped reinforcing member has a socket 94 secured at the base of the U, and an opening 96 in the formation 90 gives access to the interior threaded portion 98 of the socket 94. Each side of the vehicle has a structure similar to that shown in Figures 2 and 4 so that the bumper may be attached at the two sides of the vehicle.

Adjacent the rear end of the narrower portion 36 a downward depression or pocket I00 is formed. This depression is for the purpose of receiving the lower end of the spare tire which is secured to the inside of the rear door 4. The transverse member 50 at the center of the vehicle is slightly curved or arched as indicated at I02 to cause the transverse member to conform to the shape of the depression I 00. The flange 48 of the transverse member 44 is likewise curved as indicated at I04 to conform to the curvature of the pocket I00.

The mounting for the rear shackles of the rear springs 30 is shown in Figure 2. The side channel section has mating openings at its top and bottom between which tubes I06 extend. The top face of the channel is slightly depressed and receives the plate I08 which is provided with inwardly extending cylindrical portions IIO which fit in the top openingsand project into the tubes I06. A similar plate I08 is applied at the bottom which has similarly provided cylinder portions H0 which extend inwardly of the tube from the bottom. These plates I08, the tubes I06 and the channel portion are rigidly welded together. The bolts to secure the. shackles in place are passed through the tubes I06.

An opening I I2 for the reception of the gasoline tank is provided in the rear of the narrow section 36 immediately ahead of the tire depression I00.

Fitting in depressions in the side edge of the narrow portion 36 are the rectangular plates I I4 (Figure '7) having openings II 6 which fit over corresponding openings in the lateral box section and to which there is applied a structure similar to the structure shown in Figure 2 for the mounting of the rear spring shackle. The structure at II 4 and H6 is for the purpose of mounting the shock absorbers.

By referring to Figure 5 it will be noted that the narrower rear section 36 extends upwardly from the line of junction II8 with the wider forward section 34. The rear part 36 extends upwardly to the point I20 and then rearwardly to the point I22 and then downwardly so that the rearmost end of the vehicle is substantially in the same plane as the forward widest part 34 of the underpan. The upward bending of the rear narrow portion 36 is to provide a kickup for the rear axle to permit the rear axle to move up and down in response to uneveness in the road and flexure of the springs. At the line I20 the box-sectioned constructions at the sides of the rear section 36 are reinforced by the channel irons I24 indicated in dotted outline in Figure '7 and in full lines in Figure 8. These U-shaped members are relatively short and are spot-welded to the adjacent sides of the box-sectioned construction. Their purpose is to strengthen the construction at the point where they are applied.

Immediately over the rear axle the rear and narrow part is provided with a pressed-out portion or bulge I26 to accommodate the differential housing. Transversely the rear section is also provided with the upwardly pressed transverse channel I23 which on its underside has welded at the sides thereof a plurality of plates I 30 (Figure 6) to strengthen and reinforce the construction.

At the extreme forward end of the narrow portion 36 or immediately to the rear of the line II8 where it joins onto the forward section the rear section is formed with a tunnel shaped member I32. There are also provided a plurality of ribs I34 to strengthen the inclined portion between the lines H8 and I20.

Transversely of the underpan at the line of junction 8 the pan is provided with an inverted U-shaped reinforcing member I36 which extends the full width of the vehicle. The rearmost leg I38 of the element I36 has the rearwardly extending short flange I40 which abuts against the narrow portion 36 and is welded thereto. The forward leg I42 has the narrow flange I44 which abuts again-st the forward broader part 34 and is welded thereto. The web I46 of the transverse mem'ber' I36 is substantially in a horizontal plane and forms a support for the front portion of the rear seat. A plurality of lightening openings I 48 are provided in the member I36, each lightening opening having an inturned flange as best shown at I50 in Figure 5,

a the purpose of the flange I50 being to strengthen the construction. a

The forward wider portion 34 has formed therein a plurality of ribs I52 to strengthen the construction. On the center line of the part 34 a cutout section I54 is provided. This cutout section is relatively wide and is for the purpose of accommodating the propeller shaft I56. Tostrengthen the underpan at the cutout I54 and to protect the propeller shaft a tunnel I 58 is provided. This tunnel is arched as is best shown in Figures 14 and 15 and has its sides I60 terminating in the lateral flanges I62 which extend under the edges of the cutout portion I54 and are s'pot-Welded'thereto to form a rigid construction. The tunnel I58 extends from the transmission at the front of the vehicle to the transverse reinforcing element I36 as is best shown in Figures 5, 6, and '7. At its rear end where it meets the: transverse member I36 it telescopes" into the end of the short tunnel I32 of the rear element 36 and is welded thereto at the overlapping'flan'ges I64. Where the transverse member I36 meets the tunnels I32 and l'58' it is provided with anarchedportion to accommodate commodate the transmission which extends, far

enough rearwardly from the rear engineto be received in the underpan 32. At the diverging part I10 the edges of the underpan are offset downwardly as indicated at I12 (Figure 9) and are provided with a plurality'ofopenings I14. On the offset flanged edge I12 there is-received the flange I16 at the edge of a transmission cover I18. The cover I18 is also channel shapedas is best shown in Figure 9 and forms a continuation of the main central channel I58. Theforward end of the channel I58 has the offset flange I80 which extends into the end of. the transmission cover I18 and is welded thereto. The forward edge I82 is inclined and conforms to the incline of the toeboard of the vehicle. The toeboard (not shown) is of metal and has the forward edge I82 welded thereto. The transmission cover I18 is secured to the underpan by means of bolts I64 which pass through the overlapping flanges and through frame members I86 forming a part of the detachable foreframe of the vehicle. A suitable anti-squeak material (notshown) is used between the flanges I12 and I16 and between the flange I12 and the frame membersI86.

The f.oreframe of the vehicle comprises the .two innerelements I86 andthe two outer'ele- Inents I88 each pair I86-I88 being generally of Y shape and having the wider portion of the Y edge is a channel member I90. The upper flange I92 of the channel I90 is welded to the edge of the pan as indicated at I94 while the bottom flange I96 has no direct connection to the pan. The structure is best shown in'Figures l and 11.

Referring to Figures 5, 6, '7, and 10, it will be seen that at the forward portion of the pan a bracket I98 is secured to the interior of the channel I90 by welding. This bracket has the general configuration shown in Figure and there are secured in mating openings in the channel I90 and in the bracket I98 the socket 200 whichis interiorly threaded and adapted to receive bolts which are threaded into the socket 200 and into the outer frame member I88. In this manner the outer frame members I88 are removably attached to the underpan. The mouth, of the Y of each lateral frame pair I86-I88 is joined by a tube I shown in Figure 5.

Under the openings of the doors II and I2 a more or less channel shaped shell 202 is applied. The shell 202 has the upper flange 204 'spot;-weld ed to the upper portion of the main web of the channel I90" while a bottom flange 266 is welded to the lower flange I96 of the channel I90. The

to the vehicle.

shell, 202 has the offset portion or recess 208 which forms a jamb face for the overlap flange 2I6 of the doors II or I2.

Extending underneath the pan and for the full transverse width of the front wider portion 34 are two channel shaped reinforcing braces or ribs 2I2 and 2I4. Both of these ribs are downwardly arched as indicated at 2I6 and 2I8 where they meet the tunnel I58. The rearmost brace 2I4 is downwardly arched to a greater extent than the forward brace for the reason that the propeller shaft I56 has a greater are of movement relative The braces 2I2 and 2M have lateral edge flanges 220 by means of which they are spotwelded to the bottom of the underpan part-36. The ends of the braces 2I2 and 2I4 have the flanges 222 which are outwardly turned I90. This structure is best shown in Figure 13.

Referring to Figure '7, there is shown at 224 the place at which the forward edge of the rear spring is secured to the underpan. The structure here is substantially the same as that shown in Figure 2 for, the mounting of the rear spring shackles.

In Figure 6 part 226 is to support the hand brake or emergency. brake cable and part 228 is to support the oil line for the hydraulic brakes.

I claim:

1". In an automobile body, an underpan extending'the length of the body, downturned edge flanges at the rear of the underpan, longitudinal channel shaped members secured to the pan edge and to the flanges and forming therewith a boxsectioned construction, door posts, said channel members extending from the rear of the pan to said posts.

2. In an automobile body, an underpan extending the length of the body, said pan having a narrow rear part and'a wide front part, downturned edge flanges on the narrow rear part,

- longitudinal channel shaped memberssecured to the flanges and to the pan and'forming therewith a box-sectioned construction, door posts at both sides of the body at the Wider part of the underpan, said channels extending from the rear edge of the narrower section and terminating at the door posts of the wider section.

3. In an automobile body, an underpan extending substantiallythe full length of the body, a

downturned flange at the rear edge of the pan, a

transverse plate secured to the underpanand extending downwardly therefrom and spaced from the'flange, a second transverse plate extending across the rear of the vehicle and secured to both the flange and the first-mentioned transverse plate and forming therewith a box-sectioned construction extending across the rear of the .underpan, a depression formed in said lastnamed transverse plate and having one of its sides abutting the flange and secured thereto.

4. In an automobile body, an underpan extendving substantially the full length of the body, a

downturned flange at the rear edge of the pan, a transverse plate secured to the underpan and extending downwardly therefrom and spaced from ment secured to the abutting parts of the depression and the flange.

5. In an automobile body, an underpan extending substantially the full length of the body, a downturned flange at the rear edge of the pan, a transverse plate secured to the underpan and extending downwardly therefrom and spaced from the flange, a second transverse plate extending across the rear of the vehicle and secured to both the flange and the first-mentioned transverse plate and forming therewith a box-sectioned construction extending across the rear of the underpan, a depression formed in said lastnamed transverse plate and having one of its sides abutting the flange and secured thereto, and a rear door sealing member secured to the abutting parts of the depression and the flange.

6. In an automobile body, an underpan extending substantially the full length of the body, said pan having a narrow rear part and a wide front part, downturned flanges at the side edges of the rear part, channels secured to the flanges and the pan and extending forwardly to the wide part and secured thereto, said channel forming with the narrow and wide parts a box-sectioned construction extendingalong the sides of the underpan, said narrower part of the frame having a kickup or upturned part to accommodate the vertical movement of the rear axle, and U- shaped strengthening reinforcements in the boxs ectioned construction to reinforce the same at the bends in the kickup.

7. In an automobile body, an underpan extending substantially the full length of the body, said pan having a narrow rear part and a wide front part, downturned flanges at the side edges of the rear part, channels secured to the flanges and the pan and extending forwardly to the wide part and secured thereto, said channels and front and rear parts forming a box-sectioned construction extending along the edge of the underpan, said narrower part extending upwardly and rearwardly where it joins onto the wider part, and a U-shaped transverse reinforcing member extending across the pan and having flanges at the ends of the legs of the U, one flange being secured to the narrow frame part and the other flange to the wide frame part.

8. In an automobile body, an underpan extending substantially the full length of the body, downturned edge flanges on the underpan, a channel member secured to the pan edges and to the flanges and forming therewith a box-sectioned construction, a reinforcing member inside the box-sectioned construction at the rear'of the underpan, and means at the rear end of the pan secured to the box-sectioned construction and the reinforcing member on which to mount a bumper.

9. In an automobile body, an underpan extending substantially the full length of the body, flanges at the side and rear edges of the underpan, channel members secured to the sides of the underpan and to the flanges and forming therewith box-sectioned constructions, a transverse plate secured to the pan at the rear end thereof and extending between the side boxsectioned constructions, and a second transverse plate connecting the rear flange of the pan and the first-mentioned plate and forming with the rear flange and the plate a box-sectioned construction, both said plates being secured to the side box-sectioned constructions. v

10. In an automobile body having side doors,

'nels secured by one of their flanges to the edge of the wide part and extending the full length of the wide part, substantially U-shaped outer shell members, one member over each of said channels and forming therewith a box-sectioned construction, said U-shaped member being secured to the channel and extending the width of the doors only, and a door jamb face formed on said U-shaped member.

1-1. In an automobile body, an underpan extending substantially the full length of the vehicle', said underpan comprising a wide front part and a narrow rear part, said rear part extending upwardly from the line of junction with the wide part, a cutout part extending the full length of the middle of the said part, an arched tunnel over said cutout part, said tunnel being secured to the pan at the edges of the cutout part, the rear end of said tunnel being secured to the upwardly inclined narrow rear part, transverse reinforcing members on the underside of the pan extending the full width of the wider part said members being downwardly arched under the tunnel to accommodate a drive shaft.

12. In an automobile body, an underpan extending substantially the full length of the vehicle, said underpan comprising a wide front partand a narrow rear part, said rear part extending upwardly from the line of junction with the wide part, a cutout part extending the full length of the middle of the wide part, an arched tunnel over said cutout part, said tunnel being Secured to the pan at the edges of the cutout part, the rear end of said tunnel being secured to the upwardly inclined narrow rear part, transverse reinforcing members on the underside of the pan extending the full width of the wider part, said members being downwardly arched under the tunnel to accommodate a drive shaft, and a transverse reinforcing member on the upper side of the pan at the line of junction of the wider and narrower parts.

13. In an automobile body, an underpan extending substantially the full length of the vehicle, said underpan comprising a wide front part and a narrow rear part, said rear part extending upwardly from the line of junction with the wide part, a cutout part extending the full length of the middle of the wide part, an arched tunnel over said cutout part said tunnel being secured to the pan at the edges of the cutout part, the rear end of said tunnel being securedto the upwardly inclined narrow rear part, transverse reinforcing members on the underside of the pan extending the full width of the wider and to make a box-sectioned construction at the rear, and a member projecting from the flange and forming with the door a weather seal.

RUSSELL s. BEGG. 

